Question: Can you diagnose cancer by looking at the gut?

Ciarán O'Brien answered on 17 Nov 2014:

Some kinds of cancer, yes. You can get cancer anywhere in your gut if you’re very unlucky, so looking at the gut is really the best way to diagnose that :p

You could use it to diagnose some other types too, but there are probably better ways to do it. A lot of cancers will result in your blood having extra numbers of white blood cells or some kind of chemical you’d only find in cancer patients (the fancy name we use for them is ‘biomarkers’), and these would show up in someone’s gut or poop as well, but you’d get a much more accurate result by looking at someone’s blood.